The present invention relates to a developing sleeve used in a developing apparatus of an image forming device of a type in which electrophotography is applied, such as a photocopier or a printer, a developing apparatus which is equipped with the developing sleeve, and an image forming device equipped with the developing apparatus.
The developing apparatus of an electrophotographic device comprises a developing sleeve generally made of a metal or rubber, for carrying a toner, charging it and conveying it to a photoreceptor. In the case of a metal-made developing sleeve, the surface of the sleeve is subjected to a sandblast treatment to impart an appropriate surface roughness.
However, the conventional metal-made developing sleeves entail the following drawbacks.
That is, in each of the conventional developing sleeves, the sandblast treatment is carried out on their surface in order to impart a certain roughness thereto, thus obtaining a toner conveying ability. However, in the case where it is made of a metal such as stainless steel, the surface is made very hard, and therefore it is very difficult to carry out the sandblast treatment. Further, in the case where Al is used for the sleeve substrate, the surface is made soft and therefore it is easy to carry out the sandblast treatment. However, the surface has a poor anti-abrasiveness and therefore a problem of durability occurs.
It is an object of the present invention to provide a developing sleeve having an excellent developer conveying ability and an excellent durability even without carrying out a sand-blast treatment or the like on its surface.
It is another object of the present invention to provide a developing apparatus equipped with a developing sleeve having an excellent developer conveying ability and an excellent durability.
It is still another object of the present invention to provide an image forming apparatus including such a developing apparatus, which can maintain a sufficient image density in a long period of operation.
According to the present invention, there is provided a developing sleeve comprising a metal substrate of a sleeve shape; and a ceramic-dispersion-plated metal film containing ceramic particles dispersed therein and formed on a surface of the metal substrate.
Further, according to the present invention, there is provided a developing apparatus comprising a container containing a developing agent; a developing sleeve described above, provided in the container; a supplier, provided in the container, for supplying the developing agent to the developing sleeve; and a regulating member regulating a thickness of a film of the developing agent, carried on the surface of the developing sleeve.
Still further, according to the present invention, there is provided an image forming apparatus comprising a photoreceptor; a charger charging a surface of the photoreceptor; an exposing device exposing the surface of the photosensitive, which is charged, thereby forming an electrostatic latent image thereon; a developing apparatus described above, provided to face the photoreceptor, for developing the latent image, thereby forming a developing agent image; and a transfer device for transferring the developing agent image onto a transfer medium.